Boil a large pot of water over high heat. Once boiling, add gluten-free macaroni and cook for 7-8 minutes until al dente. Drain and rinse with cold water to cool.

In a mixing bowl, combine hearts of palm, red pepper, corn, and peas. Toss gently to mix.

In a small bowl, whisk together Dijon mustard and mayonnaise until smooth and creamy.

Add cooled macaroni to the vegetable mixture, then pour dressing over. Fold gently to combine without mashing the vegetables.

Taste for seasoning, adding salt and pepper as needed. Cover and chill in the refrigerator for at least 30 minutes.

Serve the salad cold, scooping portions into bowls or on a platter.